Interpretive Summary: Dicyclanil is an insect growth regulator used in veterinary medicine for the prevention of myiasis or fly-strike, a disease resulting from the infestation of tissue by fly larvae, in Europe, the Middle East, and Africa. Residues of dicyclanil in food animal tissue may be a food safety issue since dicyclanil-induced hepatocarcinogenesis has been observed in mice. This paper demonstrates the development of an enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies from rabbits for the determination of dicyclanil residues in sheep muscle, liver, kidney, and in milk. Antibodies are substances that are produced by the immune system in response to foreign substances which enter the body. Once the antibodies to a foreign substance are isolated, they can be used in a method to detect the presence of that foreign substance. The homogenized meat samples and milk samples were extracted, and the extracts were analyzed with the ELISA. The mean recoveries of dicyclanil were between 52.5% and 72.4%. The developed dicyclanil analysis method was rapid, sensitive, and reliable. The results demonstrated that the developed method can be used as a screening method to quantify dicyclanil residues in animal tissues.

Technical Abstract:
Dicyclanil is a pyrimidine-derived insect growth regulator used in veterinary medicine for the prevention of myiasis or fly-strike. It is toxic to animals and humans. In this paper, for the first time, a competitive indirect enzyme-linked immunosorbent assay was developed for the determination of dicyclanil in animal tissues. The antigen was prepared using the glutaraldehyde method and polyclonal antibodies were obtained by immunizing rabbits with a dicyclanil-BSA conjugate. The antibody obtained was specific for dicyclanil with an IC50 at 9 ng/mL. Recoveries from sheep tissue and liquid milk were in the range of 52.5–72.4%, with CVs between 4.7% and 11.9%. The results were further confirmed using UPLC–MS/MS.